WASHINGTON – The Senate is backing President Barack Obama’s efforts to ramp up the war in Afghanistan, granting his request for $91.3 billion for military and diplomatic operations there and in Iraq.

The spending bill, approved on an 86-3 vote Thursday night, goes to congressional negotiators to work out a compromise with a similar measure the House passed. Lawmakers expected to present a bill for Obama’s signature next month. &#187 Department of Defense

The major difference in what Obama sought and what the Senate granted concerned the $80 million the president wanted for closing the U.S. detention facility at the naval base at Guantanamo Bay, Cuba. The Senate joined the House in blocking the president’s plan for closing the prison until he submits a detailed plan for the disposition of the terror suspects held there.

Obama is sending more than 20,000 additional troops to Afghanistan. For the first time, the annual cost of the war in Afghanistan is projected to exceed the cost of fighting in Iraq.

With support forces, the number of U.S. troops in Afghanistan is expected to be about 68,000 by the end of the year – more than double the size of the U.S. force at the end of 2008.

Among the few cautionary voices during debate over the spending measure came from Sen. Barbara Boxer, D-Calif.

“I want to give this administration … the resources it needs to successfully end these wars,” Boxer said. “I don’t support an open-ended commitment of American troops to Afghanistan. And if we do not see measurable progress, we must reconsider our engagement and strategy there.”

Debate pretty much fizzled after Democrats retreated and moved to delete from the bill money to close Guantanamo, where about 240 terrorism suspects still are held.

The underlying war-funding measure has gotten relatively little attention, even though it would boost total approved spending for the Iraq and Afghanistan wars above $900 billion.

The Pentagon would receive $73 billion under the legislation, including $4.6 billion to train and equip Afghan and Iraqi security forces; $400 million to train and equip Pakistan’s security forces; and $21.9 billion to procure new mine-resistant vehicles, aircraft, weapons and ammunition, among other items.

The House version adds $11.8 billion to Obama’s request, including almost $4 billion for new weapons and military equipment such as eight C-17 cargo planes, mine-resistant vehicles, Bradley Fighting Vehicles and Stryker armored vehicles. The House measure also adds $2.2 billion to Obama’s request for foreign aid, much of which appears to be designed to get around spending limits for 2010.

The Senate measure contains less for weapons procurement and foreign aid, setting up potentially nettlesome negotiations.

The Senate floor was often empty Thursday as senators wrestled privately over what final add-ons would make it into the bill.

In the end, several amendments were added, including one by Sens. Joe Lieberman, I-Conn., and Lindsey Graham, R-S.C., to block the release under the Freedom of Information Act of government photographs showing the abuse of detainees. The administration is fighting the American Civil Liberties Union in federal court over the release of the photos, and the move was intended to bolster the government’s legal position.

Sen. Bob Corker, R-Tenn., won approval of an amendment requiring the president to set forth U.S. objectives in Afghanistan and Pakistan and issue quarterly reports detailing whether those goals were being met.

The Senate bill includes $1.5 billion as cautionary funding to fight a possible flu pandemic, including the current outbreak of H1N1 swine flu.

The bill also contains $350 million for various security programs along the U.S.-Mexico border. But the money would not be awarded to the Pentagon, as Obama requested.

By a 64-30 vote earlier Thursday, the Senate rejected an amendment by Sen. Jim DeMint, R-S.C., to kill a proposed $100 billion line of credit for the IMF to shore up the ability of countries around the globe to cope with financial crises, along with $8 billion for existing commitments.